This invention relates to an apparatus for printing or exposing an image or images of an original plate on a photosensitive material such as film, presensitized plate, etc.
In graphic art works, it is often required to print one image repeatedly and successively onto discrete areas of a sheet of photosensitive materials from an original negative/positive (hereinafter defined as "original film"). For such purpose, an apparatus so-called "composer" is generally used, which is well-known to use for step-and-repeat exposure operations. An original film holder by which an original film is fixedly placed is moved to desired positions on a sheet of photosensitive materials, at which a contact exposure is made. The original film holder is required to be larger in size than an original film so as to efficiently hold the original thereon. As the result, for example, in the event that two relatively large-sized images are discretely printed side by side on a sheet of photosensitive materials, or in the event of printing from an original film with non-standard size, it is unavoidable to change the holder to another one suitable to the original film size, resulting in a larger-sized apparatus as a whole and in much expensive.
It is also required in graphic art works to print several images of different original films on a sheet of photosensitive materials. In such operation it is indeed possible to carry out the printing operation by using a composer whereby an original film is automatically replaced with another one, however, this unavoidably requires the large-sized apparatus which is expensive.
In order to carry out the foregoing kinds of printing operations, a so-called vacuum printing apparatus has customarily been used wherein the original film is manually positioned. Such operations in the prior arts are much complicated, the accuracy thereof being not sufficiently obtained, and increasing demands for automating graphic art works are not met under the present situation.